After r251874, properties from class extensions no longer show up in
ObjCInterfaceDecl::properties(). Make debug info emission explicitly
look for properties in class extensions before looking at direct properties.
Also add a test that checks for this. There are three interesting cases:
1. A property is only declared in a class extension, and the @implementation
is in a different file. This used to generated a DIObjcProperty before
r251874 and does again with this fix.
2. A property is declared as readonly in the class itself and redeclared as
readwrite in a class extension. clang before r251874 put the DIObjcProperty
on the first declaration. clang after r251874 didn't emit any DIObjcProperty,
and clang with this fix puts it on the readwrite redeclaration (which is
what lookup finds). This seems like a progression.
3. Like 2, but with an @implementation in the same file. In this case,
the property debug info gets generated a second time through the ivar
from the definition. In this case, lookup and declaration code need
to agree on the line number so that the DIObjcProperty isn't emitted
twice. In this case, clang before r251874 emitted one DIObjcProperty
on the first declaration, clang with r251874 emitted one on the second
declaration, and clang with this patch still does the latter.
llvm-svn: 254750